Increase the usefulness of the data generated in projects related to the diagnosis of human breast cancer. A central file was developed by the contractor for the breast tumor biomarkers program. The file allows preparation of various serum panels for testing new biological markers for breast cancer, setting up studies on multiple markers involving multiple institutions, and comparisons of the results from various studies and provides a database from which material can be quickly and conveniently retrieved. This data file also is intended for testing new ideas, identifying groups ofsubjects suitable for more detailed study, and for preparing reports to the medical community and the general public.